Vibratory system for the transmission and reception of sound waves



Ap 1939- F. 'w. KALLMEYER 2,153,571

VIBRATORY SYSTEM FOR THE TRANSMISSION AND RECEPTION vOF SOUND WAVES Filed April 11, 1936 J72 vezztor: 501349166 MIhQ/M k qmyek Patented Apr. 11, 1939 UNITED STATES vmaa'ron'v SYSTEM SION AND RECEPTION Friedrich Wilhelm Kallmeyer, assignor to Atlas-Werke Bremen, Germany Application 5 Claims.

It has already been proposed to use in the construction of magnetostrictive vibratory system tubular members made of a magnetostrictive material, which are connected to diaphragms or terminal masses. tional forms either a single tube was used or several tubes were mounted next to one another on a common plate. This construction has this disadvantage among others, that it is diflicult to obtain magnetic circuits which extend almost. completely in the magnetostrictive material. When only a single tube is used, the magnetic circuit can only be completed through yokes, 01' slots have to be cut in the tubes andthe bridgeshaped parts thus formed separately wound. If a plurality of tubes be used, a fairly large number must be employed, as, with the use of only two or three tubular bodies, ture of the vibratory body results and the dis-- tribution of the flux entails difilculty.

According to the present invention in a vibratory system for the transmission and reception of sound waves with two or more longitudinally' vibrating, tubular magnetostriction vibrators, the ends of which are connected to a diaphragm, more particularly a piston diaphragm or a terminal mass, the tubular vibrators are disposed concentrically with respect to one another and enclose between their walls one or more cylindrical coils in such a manner that their axes coincide with the tube axes. ment it becomes possible to cause-the magnetic flux to extend over the greater part of its path in the magnetostrictive material. If the circuit is. to be completed it is only necessary to interpose in the space between the walls of the concentric tubes above and below the cylindrical coil rings of this magnetostrictive material. This constructional form of the vibratory system has the further advantage, that it allows of a ready adaptation to the circular construction of the diaphragm. A further advantage is that the vibratory system has great rigidity to buckling.

Preferably the diameter of the tubes will be made equal to or greater than half the diameter of the piston diaphragm connected withthem, in order as far as possible to prevent non-sinusoidal vibrations. The vibratory system may he so constructed that the tubular vibrator is connected with one of its ends diaphragm and with its other end either vibrates freely or is loaded by a mass. A constructmnal form may also be used with advantage, in which the end lying opposite the piston diaphragmis .connected with the casing as the abutment, either In the hitherto known construcan unsymmetrical struc- With this arrangerigidly to the piston I FOR THE TRANSMIS- OF SOUND WAVES Bremen, Germany, Aktiengesellschaft,

April 11, 1936, Serial No. 73,886 Germany Apr-ll 13, 1935 under pressure or notfThe connection of the vibratory system with the diaphragm may also be established in the same way. The tubular vibrator will then be interposed in a stressed state be:-

, part of the piston diaphragm 5 and the oppositely disposed part of the casing wall, but so as to be capable of being easily re moved at any time.

The invention is illustrated by way of example in the accompanying drawing, in which,

Fig. 1 shows a vibratory system with a tubular vibrator standing freely on the diaphragm and Fig. 2 another constructional form in which the tubular vibrator is connected at the inner end with the casing. V In Fig. 1 of the drawing l is a cylindrical casing which is closed at "one end by a pistondiaphragm 2, while at the other end a closing cover 3 having a cabled with a bushing is provided. On the piston diaphragm 2 is fixed a magnetostriction tubular vibrator which consists of two concentric tubes 5 and 6. These tubes are made of sheet nickel having a thickness of about 0.5 mm.

ened middle part of the piston diaphragm 2. The walls of the tubes are preferably provided with longitudinal slots I, for preventing as far as possible the formation of eddy currents. Be-

tween the walls of the tubes 5 and 6 a cylindrical coil 8 is arranged. The leads 9 and I0 to the-, cylindrical coil are taken through slots in the outer tube. For establishing a good magnetic circuit narrow rings II and H of magnetic'material are'inserted above and below the coils so as just to make contact with the walls of the two tubes. These rings have radial slots for preventing eddy current losses. Pads l3 and H of spongy rubber which are pushed lightly between the tubes prevent the rings from falling out or moving within the space between the tube walls. The longitudinal slots in the tubes are preferably extended beyond the place where the cylinders H and I2 establish a magnetic circuit, as will be 4 seen from the drawing. The freeend of the tubular vibrator may be rigidly connected with terminal masses for varying thedamping and tuning of the vibratory system. s

In Fig. 2 a similar vibratory system is shown. The. casing is formed by a cylindrical part vs, a piston diaphragm l6 and a closing cover l1. On the piston diaphragm l6 ismounted a magnetostriction tubular vibrator consisting of three concentric tubes l8, l9 and-21L Between the three in the same manner as 55 nected in series or parallel. At one end of the 2. A magnetostrictive transmitting and receivtubes a ring-shaped mass 23 is soldered on, to lug device comprising a casing having a diawhich the coils 2| and 2 2 are so connected asto phragm at one end thereof, a plurality of conextend freely between the walls of the tubes. In centric cylinders mounted on said diaphragmthe casing above this ring-shaped mass 23 a vwith their axes at right angles to the radiating is threaded ring'u is provided, by which the tubu'- surface of the diaphragm, a plate carrying a plular vibrator can be pressed against the thickened --rality of coils adapted to be positioned parallel middle part of the pistom diaphragm I 6. to the cylinders and means threading into said In another constructional form the tubes of casing and bearing on said plate whereby the l0 magnetostrictive material are rigidly soldered to coils remain concentrically positioned with re- 10 the piston diaphragm and by means of the. spect to said cylinders and the desired pressure threaded ring 24 pressure is exerted on to the is placed on said diaphragm through said cyl-- other end, so that the piston diaphragm I 6 is inders. a given a certain initial stressing and in this way 3. A magnetostrictive transmitting and receivthe vibrator is rigidly connected to the casing. ing device comprising a cylindrical casinghav- 15 The vibratory system can be used both as a ing a diaphragm at one end thereof, a plurality transmitter and as a receiver for the production of n ntri rings posi ioned con en rically of and the reception of sound oscillations, more within said casing on Said d ap a wi their particularly in water. When used as a receiver, ax s at right angles to the radiating surface of the piston diaphragm should have as small a the diaphragm, a plate, means adjustably posi- 20 massas possible. As, however, in view of the m d o bea in upon saidpIa and p l y requisite stiffness thethickness of the diaphragm o coils positioned to occupy the spflc t etwe n mass may not go below a definite dimension, it is Successive cylinders, said coils being mounted on of importance to keep the weight which is added Said through the magnetostrlction vibrator mounted Me n o t ansmitt n and rece vin hi as on it as low\ as possible. This is ensured by the qu y p s al Waves c p n yconstruction according to the invention, for it is lindlical casing having a P sto d aphra m at possible to make the tubular vibratorin this form one a pl ral y of cylinders, pl y of extremely light. A further lt t for of concentric coil means positioned between said so the vibrator is, that the piston. diaphragm is supcylinders a d se ur sa d co n Position so ported in such a manner. that undesired forms of spectively between Sa d cy inders.

vibration of the diaphragm are as far as possible Means for transmitting and receiving high eliminated, v frequency compressional waves comprising a caswh t I olaim I lug having a diaphragm at one end, a plurality 5 1 A td tfl fl transmitting and receiv; of concentric cylinders of magnetostrictive matejng device comprising cash"; having a i 'rial mounted upon said diaphragm, a plate bearphragm t o at-h e a plurality of cylini ing upon the ends of said cylinders and having ders mounted concentrically t said diaphragm mounted and positioned thereon a plurality of with their axes at right angles to the radiating concentric cells, h coils c up osit ons one 40 surface of th d h an t t member between each or said cylinders, and a member (0 and a plate upon which the abutment member threading Within the casing and bearing upon s, a plurality of coils mounted 'on said plate Sa d plate exerting \pressureupon said cylinders and means for adjusting said abutment member through said plate. longitudinallyof said casing, said coils being po- 1 g sitioned to lie concentric with the cylinders FRIEDRICH LH KALLMEYER- '45 mounted on said diaphragm.

L CERTIFICATE OF CORRECTION. Patent Lu 2, 53 571. April 11, 1939;

1 FRIEDRICH w'ILHELn KAILI'IEYER.

Ibis hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows Page 2 second lnnn', line 29, claim i for the 'words eou means" eoo'eone; lind50,

before "securing" insert me'ans; and that the said Letters Patent should be re ad with this correction thereinithat the same may conform tothe record of' the case in the Pate t orriee. I w

signed. and sealed thialth day of May; A. D- 939.

' I 1 -l-Ie nr Van Arsdale l) lictir g coimnissioner of Patents, 

